Ten years on: An updated scoping review of relative motion orthoses for managing various hand conditions.

BACKGROUND: In the decade since the landmark Relative Motion (RM) scoping review was published, literature volume has tripled, alongside expanded applications across three categories: protective, exercise and adaptive. PURPOSE: To provide an overview of published evidence since 2016 relating to RM orthoses and integrate these findings with the 2016 review. STUDY DESIGN: Scoping review. METHODS: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews guided this study. Four databases were searched: CINAHL, Embase, MEDLINE and PubMed. Studies investigating RM use in adults with hand conditions were included. Data extracted included demographic, intervention and outcome details. Quantitative and qualitative studies were appraised using the Structured Effectiveness Quality Evaluation Scale and Standards for Reporting Qualitative Research respectively. The Template for Intervention Description and Replication checklist evaluated intervention reporting, informing a narrative synthesis. RESULTS: Twenty-two studies involving 386 participants met inclusion criteria. Quantitative studies were categorized as protective (n = 19 studies, 346 participants) and exercise-based (n = 1 study, 20 participants). Qualitative studies explored adaptive use (n = 1 study, four participants) or combined protective and exercise applications (n = 2 studies, 16 participants). Study designs included randomized control trials (n = 6), retrospective case series (n = 6), prospective case series (n = 1), clinical audit (n = 1), case reports (n = 4), qualitative studies (n = 2) and mixed-methods (n = 1). Three studies comparing RM extension with alternative approaches for zones V-VI extensor tendon repairs reported equivalent or superior outcomes. Randomized control trials found no significant difference between RM and metacarpophalangeal blocking orthoses for trigger finger management. CONCLUSIONS: Multiple randomized control trials support RM orthoses without a wrist component to adequately protect extensor tenorrhaphy in zones V-VI. Since 2016, RM literature has expanded to include a broader range of hand conditions. Further research is required to evaluate the orthosis' use in flexor tendon injuries, boutonniere deformity and sagittal band injuries.